45 Street is a typical two side platform local station on the BMT 4th Avenue Subway Line. The station got the awful 1970s cinderblock renovation that covered all of the original trim line along the station's platforms. There are the standard light-grey blocks with darker-grey indentation areas where the station's name signs are and text painted onto the walls that mostly say exit and an arrow pointing towards the station's main exit, a small mezzanine area that is accessed from a single staircase at the extreme northern end of the Bay Ridge-bound platform, and two staircases from the Manhattan-bound platform. The platforms are offset slightly from each other, the Manhattan-bound platform goes a bit farther north and the Brooklyn-bound platform at bit farther south. On the mezzanine there is some evidence of the original mosaic trim and directional arrow mosaics. One says Up Town Trains (for the Bay Ridge-bound platform) and the other Down Town Trains (for the Manhattan-bound) platform. This mezzanine has four streetstairs in total, two to both the NE and NW corners of 4th Avenue and 45th Street. These exits are painted green have the 1950s and '60s angular square designs and also have unique posts with Subway written on white glass and designed to be illuminated by a florescent lights at night. The stickers that used to cover up the N (hasn't stopped at the station except during late nigths since 2000) have fallen off many of the entrances

There is a closed exit to 46 Street (all the local stops south of here still have this High Exit Turnstile exit open) towards the middle of the Bay Ridge-bound platform. Evidence of it is by a door in the walls, and more importantly that south of the sign all the painted text on the platform columns simply say exit, while in between this closed exit and the main one arrows say 45 St next to them and painted over arrows formerly said 46 St. Both platforms also have columns along their platform lengths, all are painted blue and are round for most of the platform's length except towards the end where the platform was extended to accommodate ten-car trains and those are the standard I-bean ones. These columns all have 53 Street signs on them.